In light processing systems, crystals of non-linear materials can be used to change the frequency, and thus also the wavelength, of light to produce light of a desired frequency. For example, crystals can be used as a frequency doubler to double the frequency, and halve the wavelength, of light incident on the crystal. This process is called second harmonic generation. In such crystals, the second harmonic conversion efficiency is low at low incident light intensities, but increases with increasing incident light intensity. However, the efficiency of such second harmonic generation processes is typically low.
Accordingly, it would be desirable to provide light processing systems and methods that are able to produce efficient high harmonic conversion.